CT200U Coleman 39mph!

#4
Sorry for all the posts. Guess I'm new so can't put it all in one...

I did paint right over the red so regret that as I need to strip it all then prime and paint. I also have pretty good top end and good low end but my midrange sucks. I have a 12 tooth sprocket. Would the 13 that was provided with the TC make that better? What about a larger rear sprocket?
 
#6
The 13t would give better top end speed and a 10t better low end for climbing hills.
Low end seems great and top end is good too. I'm not sure what gives in the mid range, because I can get to about 15-20mph pretty quick then it flattens out till I hit 30 and the power seems to come back on. For $99 I might just drop a 212cc Predator in there.
 

SAS289

Well-Known Member
#7
Low end seems great and top end is good too. I'm not sure what gives in the mid range, because I can get to about 15-20mph pretty quick then it flattens out till I hit 30 and the power seems to come back on. For $99 I might just drop a 212cc Predator in there.
Wait... your TAV kit came with a 12 tooth sprocket? Did you change to 35 chain? The norm for the Coleman is that the 10 tooth that comes with the TAV is used because of the 420 stock chain.

It may not be flattening out because of the engine. It may be flattening out because of the gearing. Once the TAV starts "shifting" the rpm's will tend to drop off. The change in gearing at that speed adds extra load on the engine. If you are geared with a 12 tooth and a 50 tooth, it may be why it feels the way it does.

When I install a TAV on my Coleman I will probably end up using a 9 tooth and the stock 50 out back.

I'm not sure a predator would help. This guy reported 38 MPH with a stock predator.

[video=youtube;0g9wPSHE24U]https://www.youtube.com/watch?v=0g9wPSHE24U&lc=z12yytrzgqu0jns2223zdxey1v2lznqgd04.14973696778 72633[/video]
 
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#9
Wait... your TAV kit came with a 12 tooth sprocket? Did you change to 35 chain? The norm for the Coleman is that the 10 tooth that comes with the TAV is used because of the 420 stock chain.

It may not be flattening out because of the engine. It may be flattening out because of the gearing. Once the TAV starts "shifting" the rpm's will tend to drop off. The change in gearing at that speed adds extra load on the engine. If you are geared with a 12 tooth and a 50 tooth, it may be why it feels the way it does.

When I install a TAV on my Coleman I will probably end up using a 9 tooth and the stock 50 out back.

I'm not sure a predator would help. This guy reported 38 MPH with a stock predator.

[video=youtube;0g9wPSHE24U]https://www.youtube.com/watch?v=0g9wPSHE24U&lc=z12yytrzgqu0jns2223zdxey1v2lznqgd04.14973696778 72633[/video]
I think its the converter shifting in to high gear that is making it feel like there is a flat spot. If you can adjust when it shift to a higher RPM it might help and running a lower number gear like a 10 tooth will also help. A 13 tooth will make it worse. I think the guy in the video is having problems with his motor now and might be returning it. He was hitting around 30-33 MPH with out the converter after the motor swap. I don't think his governor was properly adjusted from the factory or something. What ever his problem, he is now saying he has some play in the crank.
 

SAS289

Well-Known Member
#10
I think its the converter shifting in to high gear that is making it feel like there is a flat spot.
My exact point just using different words. Some members have went larger on the rear sprocket to help with this issue. As big as a 72 tooth.

The way these TAV's work it would be like an automatic transmission in a car shifting (slipping it's way) from 1st to torque convertor lock up by 25 mph. Or shifting a manual from 1st to 4th at too slow a speed. The engine just can't handle it well.
 
#11
My exact point just using different words. Some members have went larger on the rear sprocket to help with this issue. As big as a 72 tooth.

The way these TAV's work it would be like an automatic transmission in a car shifting (slipping it's way) from 1st to torque convertor lock up by 25 mph. Or shifting a manual from 1st to 4th at too slow a speed. The engine just can't handle it well.
Were can I get different sprockets? All I have found is a 38 tooth. I would love to find a rim that fits a normal gokart split sprocket or an adapter. I seen one a while back for the Doodle bug.
 

SAS289

Well-Known Member
#12
Other members have commented that the 420 rear sprockets are not easy to find with a good variety of tooth sizes. I recall one comment that a supplier someone used just went out of business. And if you do find a supplier they are quite expensive. One member, Triple A Arsenal, converted his Coleman to 35 chain. He bought a blank 72 tooth sprocket and had it machined to fit the Coleman hub.

I'm not sure if you would be able to do a general search to see their older posts or if you have to join the Coleman group, but they have some pretty good info there related to their experiences with this bike.

I have zero experience buying a sprocket for a mini bike. The last sprocket I purchased was for my old RM250 that I got from Sprocket Specialists.
 
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AldoA

New Member
#13
I wouldn't personally suggest getting a predator for a performance increase solely stock for stock or TC for TC. The predator has more growly exhaust but that's about it in my eyes. The fuel tank cap is in the most annoying spot ever. You could swap your stock onto the predator and boom. Aren't stock tecumseh's 196cc's? It could've been that one sprocket on the predator was cast 1mm bigger to gain some extra mph, but not a chance it's hitting 38mph stock without some sort of limiting issue.

Your power and speed are all in the hands of your TC (without 'serious mods'). I too was confused assuming you're saying you have a 428 chain.

My friend hits 38-40mph on his ctu200 predator according to my garmin 64st.(knockoff tav2 with 8tooth) But like I said that increases was solely TC. I actually just bought him a 12 tooth 420 sprocket ***I think **** I feel like the ebay store was being shady on purpose. He has a 50t stock rear. With the 12t I'm hoping he can at least get 44ish reliably. I'm always waiting for him on my 140cc ssr. I will add granted I can't confirm or deny, he believes the characteristics change across the whole board depending on how tight/loose the chain is in terms of smooth, swift, etc behaviors of the TC.

I'm not agreeing or disagreeing with what they said, but they way I see it is like a floating point. It doesn't want to go faster or slower.

I'll try to find 420 sprockets again for the rear. I had them opened in a tab a bit ago. But it was like 45 50 62 or 70 pre cut.

Still looking.. Just gotta say how crap! Google this since I can add url's yet..

" shop.hotrodminibike Pro-Mod-Racing-Engine-212cc-Predator-Stage-3-PMRES3 "
 
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AldoA

New Member
#14
Soooooo I can't find them again. I know for a fact I did because I almost bout a 60t and it was compatible. I've searched everywhere I thought I would've before... All I can bring is.... I can't say i'd be brave enough to try unless it was very meticulously done. I guess it would be that hard with the specs I added below. I'll keep looking.


From gopowersports dot com /sprocket-48-60-teeth-41-420-chain-dual-pattern/


It works
Posted by Jay on 13th Sep 2016

I searched all over for a 60 tooth sprocket to fit on the rear drive wheel of my Coleman CT200u minibike. I wanted to gear it down slower and with more torque. I could not find a 60 tooth sprocket that fit the hub on this minibike. I took a chance on this sprocket. The hub was bigger than the OEM 52 tooth sprocket and the bolt holes didn't line up. The hub on this sprocket was bigger so it would fit around the smaller hub on the wheel and this wasn't too big of a problem. The bolt holes had to be modified so I just drilled new ones in the new sprocket. That worked. This sprocket is a little slimmer than the OEM one and the teeth are more pointed but seems to be strong enough and is working with the 420 chain I had. I've only driven it around for ten minutes since installing it but it seems to work fine. Maybe it should have five stars. I gave it four simply because it wasn't quite right for me and I had to modify it but I kind of figured that would happen going into this purchase. The price was the lowest I could find for a 60 tooth sprocket, even though I had to pay an additional $11 or so for shipping. Delivery was only a few days. Overall, this purchase from this seller was a satisfying transaction.

I had never heard of them, but do you think a spindle hub might bolt up if there's one out there? Then the options are endless..

Specs for what's needed on rear:
Size: 420 Chain
Mounting Hole Distance (center to center, bolt hole circle): 3-3/16" (80 mm) (((3.1875)))
Center Hole Diameter: 1-9/16" (40 mm) (((1.5625)))
Overall Diameter: 8-3/16"
Mounting Hole Diameter: 5/16" (x4)
 
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AldoA

New Member
#15
Okay! Im almost there.. If any of you care at this point :p I stumbled onto an Azusa product pdf. They make tons of sprockets. Low and behold https://www.OldMiniBikes.com/ sells their sprockets. They said they would have to get back to me since they didn't know the pitch off the top of their head meaning they must not be in stock, but I asked about getting 60t available. If anyone else chimes in I could let them know when they call/email what the general consensus is tooth wise. I'm starting with a 12t front before the rear, but I know i'll get there.

At this point I only got the 50t part number being BAJ_992048001. And the knowledge they sell all parts triple tree fork related from mb200 in order to put on 200u. Head stems same dia? Doubt it...

I find it a bit odd that many of their sprockets have the blanket statement of 'fits predator 212cc' with zero reference to a bike.
 
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#16
Yeah the guy who was selling 420 rear sprockets is gone..i thought of buying a blank sprocket with near centerhole size and drilling the mounting holes for another project.. my coleman has a 68t he made..6.8 to 1. takes off smooth and will do close to 40mph @ 4500. cruises nice at 30..i like the midrange scat of a clutch..i only ride the flats..if OldMiniBikes can get other sprockets that would b nice.
 
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AldoA

New Member
#17
Can you /someone measure the center of a bolt to the adjacent bolt and then do them 180 apart. The center hole diameter and the bolt hole diameter. I believe I already have a spec sheet on it, but I had my friend's sister measure hers and everything was way off. OldMiniBikes.com is out of the picture. Sadly the guy I spoke to was also wrong about have mb200 suspension parts too :(.

I'm gonna go to the source but some feedback on sizes would be nice. So I'll wait for that. I have no clue what to even guess. I'll throw out 40 45 60 and 70...?



I sent this after she asked what a sprocket was and she gave me the dimensions of 2.5 and 3.5, which I thought was way wrong, but noted below it looks pretty legit although not perfect. shave an 8th off or so. I must either not understand center of bolt to center of bolt or which ever site I pulled those specs from was just wrong.
136.jpeg [/SIZE]
 

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AldoA

New Member
#18
Well I heard back from the individual at OldMiniBikes and he said "Mini bikes are slugs, buy pitbikes and save your backs from aching". Then mumbled on about free sprockets for everybody.. No wait.. That was me.. ;)

He truthfully said and I hope it's okay to post.. "I sell every sprocket available from Azusa, but none of them will bolt onto the Coleman flange. Here is a 60 tooth that might fit if redrilled
https://www.OldMiniBikes.com/steel-sprocket-60-tooth-41-chain.html
I can get custom sizes from Azusa, but they are a bit expensive and are not drilled with the proper pattern, and come with a 1" bore"
 

AldoA

New Member
#20
You're correct. Follow the plans I posted and it should be easy. Easier yet if getting a 'bolt hole circle' to be the same it'll super easy! The bolt holes are all 2 inches apart and I found tons off sprockets like that. Then it's ID of sprocket that theoretically just has to be below 2.25" or 57.15mm's. I was on a roll the other day finding them but didn't post any :/ if anyone cared I could.

IMG_20170703_025449.jpg
 
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